I am using a AC 130 F1 5 1/4 inch mid/woofer in a 3 way system (SB34 woofer and 27TAC/BG tweeter) I am crossing over at 2900hz to tweeter. Is that too high? Should I attempt to be lower, say 1900hz? I am getting an irritating sound that I can not put my finger on and wonder if it is beaming....Thanks
Have you tried listening to the mid only and then the tweeter only? Ben (@wolf_teeth) used that tweeter in one his builds HERE. He crossed @ 2.5 KHz, LR2 and used Fs compensation. I'm sure he'd answer any questions about best use for that tweeter.
First isolate which driver is causing it. I did not have any issues of that sort in either build with the 27TAC. The AC130F1 has a benign breakup, but it usually isn't used that high.
JeffB crossed it at 1.8kHz with the RS28A. My guess, Lowe the xover to below 2.5k, and see how that goes.
JeffB crossed it at 1.8kHz with the RS28A. My guess, Lowe the xover to below 2.5k, and see how that goes.
@ernperkins I have a while back but I can not remember. I dont use Fs compensation. I'll look at the link. My concern is first, is 2900 too high for the 5 inch mid? I do see that GR Research created a table with suggested XO points by diameter. My intuition is that it is too high,.
@wolf_teeth TY. The fact that you havent seen the AC 130F1 used that high an XO provides some validation. I will do 2 things
1) install the PIO cap you recommended (I just received them) TY for the suggestion.
2) if I still hear the aberration, I will then consider moving the XO point down from 2900 to 1900.
I do have some other technical questions that I will ask in a separate thread. Thanks all
1) install the PIO cap you recommended (I just received them) TY for the suggestion.
2) if I still hear the aberration, I will then consider moving the XO point down from 2900 to 1900.
I do have some other technical questions that I will ask in a separate thread. Thanks all
To not use Fs compensation on a tweeter with no ferrofluid does the tweeter a HUGE disservice. Is there a resistor across it at all? Like in an Lpad? Then you unknowingly are using at least a little Fs compensation. This particular tweeter has a very high impedance magnitude, and it needs that to be minimized to not get excited.
If that nasality is not the sound or culprit you are experiencing, and it is found to actually be the tweeter, then it could be the ultrasonic resonance. However, most men older than 25 won't hear anything that high. I compensated for both Fs and ultrasonic in the EMP build.
I bet the issue is the tweeter Fs or the breakup of the AC130F1.
If that nasality is not the sound or culprit you are experiencing, and it is found to actually be the tweeter, then it could be the ultrasonic resonance. However, most men older than 25 won't hear anything that high. I compensated for both Fs and ultrasonic in the EMP build.
I bet the issue is the tweeter Fs or the breakup of the AC130F1.
@wolf_teeth I do have a resistor L pad on it. I am 66 with hearing loss in my right ear so...... I'll start with the AC130F1
I wouldn't call beaming irritating. I notice there are some that try to guess at it, so there are stories equating it to a torch (flashlight) being shined in your eyes or maybe mosquito like irritation.
I'd normally start with the explanation that with less woofer power at it's top end, tonally speaking the treble will be less supported by the harmonic fundamentals.
Now this tonal imbalance can be annoying enough, but for all we can be sure of you might be hearing something else. Are you sure of your phase relationship over the wider crossover region? What about the nature of the acoustic slopes of each way?
Indeed! Folks seem to forget (not know?) that the lower the fundamental, the wider its BW, so to tonally balance a speaker we ideally need to roll off an increasingly wider HF BW as F-3dB is raised at the low end.
I've seen measurement of that midwoofer that suggest there are strong rsonances from about 1800Hz, I can't find them back, but i considered that driver also in the past, but skipped it for that. As it's a polycone driver, rsonances are damped a lot more than hard or paper cones, but still cause distortion rises onto those frequencies.